The present invention is related to a voltage reference source and a method for generating a reference voltage.
Integrated circuits often comprise a voltage reference source which generates a reference voltage. The reference voltage can be a signal with a low temperature dependency. The reference voltage should be realized as a low noise voltage.
Document U.S. Pat. No. 7,242,240 B1 describes a low noise bandgap circuit. The bandgap circuit comprises a plurality of cells. Each cell is formed of a plurality of bipolar transistors which form an amplifier. The amplifier generates a voltage that is proportional to the absolute temperature, abbreviated as PTAT. The plurality of cells is sequentially connected to add the voltages generated by each cell.